A word or two of explaination are in order about the use of "starter
recipes." These recipes are quite unlike almost all recipes in that
in them one is trying to "create life". Well sort of. A sourdough
culture is a living thing, or at least a collection of millions of
living micro-organisms. In actuality these recipes are not really
the whitchcraft that they may at first seem to be. While we may not
be able to create these micro-organisms, we may be able to atract them,
or even hunt them down in their own environments, and domesticate them
or subject them to slavery. ;^)
Most sourdough cultures contain some species of yeast, and at least
one strain of lactobacilli. These micro-organisms are found in many
places in the environment around us. You may recognize lactobacilli
as one of the bacteria that makes yogurt. Various strains or species
of lactobacilli are also involved in making sour cream, cheese, butter-
milk, and other cultured milk products. Sometimes lactobacilli is to
blame when milk just goes sour. Hence some sourdough "starter recipes
use milk to help attract lactobacilli, and some actually use ingredients
like yogurt to introduce lactobacilli.
Different species or strains of lactobacilli are responsible, in large
part for the different flavors and textures of the many different
varieties of cheese and other cultured milk products. Similarly
different strains or species of lactobacilli are mainly responsible
for the different flavors produced by different sourdough cultures.
Lactobacilli are also responsible for making sauerkraut, brine cured
pickles, and borscht. Usually the lactobacilli used in these recipes
is on the vegetables at the time they are harvested. Hence we would
not be too surprised to see recipes calling for the use of grape leaves
or some other vegetable substance.
Often times the very collection of micro-organisms we desire to gather
resides on the grain we intend to use for flour. This explains the
use of rye flour in "Manuel's Starter" or the use of whole wheat
or even unbleached white flour in a starter recipe. (Bleaching may
kill some of the micro-orgainsms.) Rye flour is almost notorious
for creating a very sour culture. (See the article on Borodin style
bread in recipe #211 below.)
The factors that determine the selection of a strain of yeast are
no less important or complicated than those which govern selection
of lactobacilli strains. For example _Saccharomyces cerevisiae_
is the scientific name given to bakers' yeast. Homebrew enthusiasts
will recognize this also as brewers' yeast. (Different strains are
used for each application. Brewers also use _S. carlsbergensis_)
_Saccharomyces cerevisiae_ does not well tolerate an acidic environment
such as is found in a sourdough culture. The lactobacilli are
constantly producing lactic acids which give the bread its sour
taste. Hence a culture that begins with active dry yeast can
never really become more than very mildly sour unless at some time
the culture is invaded by another kind of yeast.
Many (Most?) sourdough cultures contain a strain of _Saccharomyces
exiguus_, which does of course tolerate rather acidic conditions.
Hence, some starter recipes include vinegar in order to make the
batter acidic so as to prevent bakers' yeast from getting a start
and selecting in favor of _Saccharomyces exiguus_.
Location may also prove to be an important factor as some strains
of desired micro-organisms may be more prevelant in some habitats,
such as the San Francisco bay area, or Germany, for example.
Of course none of the starter recipes are guarenteed to work. These
creatures may seem to have a mind of their own. If you are unsuccessful
perhaps you might try agin, or in another place or season of the year,
or you might try another recipe.
If you are frustrated with all that, you might consider obtaining a
culture from someone who already has one. You probably have a
neighbor or relative who has a culture. Otherwise you can obtain
a culture from one of a variety of comercial sources. Also many
of the readers of this newsgroup have offered to share cultures
for as little effort required as sending a self addressed stamped
envelope (SASE) and a ziplock bag. Many of these cultures have been
in continuous use for nearly a hundred years. Some cultures (such
as the Mid-Eastern cultures from Sourdoughs International) may go
back for thousands of years. If you peruse the FAQ file FAQ.culture.bank
you will find the addresses of several comercial companies as well
as several individuals who are willing to share cultures.
Whether you decide to try to capture a new culture, or go with an
ancient one, I wish you the best of luck, and do let the group know
how things go.
Sourdough Dave (firstname.lastname@example.org)
I would like to thank Charles Delwiche for helping me to understand
much of the biology involved, however any innacuracies portrayed are
entirely my own responsibility.
Also I note that I contradict myself with respect to Manuel's starter.
(It begins with a grain of bakers' yeast.) Perhaps the hope is that
at some point a wild yeast will take over? Has anybody tried it
with out the use of any bakers' yeast?